Reanimating Bertha, a Mechanical Behemoth Slumbering Under ...

Watch Bertha, the world's largest tunnel boring machine ...

From the dark depths beneath Seattle, Bertha the SR 99 tunnel machine headed out of the muck and into daylight on Tuesday, completing a final push in a years-long effort to create space for a new highway beneath the city.

Big Bertha -- world's largest tunnel boring machine -- facing ...

Bertha (tunnel boring machine) - Wikipedia

Bertha was designed and manufactured by Hitachi Zosen Sakai Works of Osaka, Japan, and is the world's largest earth pressure balance tunnel boring machine, at a cutterhead diameter of 57.5 feet (17.5 m) across.

bertha world's largest tunneling machine - Roadheader ...

Bertha (tunnel boring machine) - Wikipedia. Bertha was designed and manufactured by Hitachi Zosen Sakai Works of Osaka, Japan, and is the world's largest earth pressure balance tunnel boring machine, at a ...

Hard grind: The epic journey of the world's biggest tunnel ...

On April 4, the world's largest tunnel boring machine broke through to the open air after almost four years underground. Called Bertha, the giant digger was tasked with the challenge of building a tunnel large enough to carry four lanes of motor traffic under the heart of Seattle.

The World's Largest Tunnel-Boring Machine | Popular Science

After a 2001 earthquake severely damaged the double-decker section of Seattle's Route 99 highway, state and city officials decided to move the main thoroughfare underground. In July, they unleashed Bertha, the world's largest-diameter tunnel-boring machine. Built in Japan and reassembled in the ...

Big Bertha: World's Largest Tunneling Machine To Be Rescued

The world's biggest boring machine Bertha is taken out for ...

Contractors building a highway tunnel under Seattle are preparing to remove the world's largest boring machine so that it can be repaired. The gigantic drill, known as Bertha, stopped working in December 2013 after digging just 1,000ft of its two-mile journey to replace the aging Alaska Way, which was damaged in 2001 by an earthquake.

World's largest tunneling machine still stuck - CNN Video

Bertha repair will take longer — there are lots of broken ...

Bertha, the world's biggest tunnel-boring machine, overheated and quit digging on Dec. 6, 2013. The machine is stuck near Pioneer Square, some 1,083 feet into the 9,270-foot route from Sodo to South Lake Union.